One of the biggest problems with the pocket computers was the place where to save programs. With the PC-1500 one solution was to get a big memory module like CE-161 or CE-163. The common system was the use of a tape recorder. But this was noisy and slow !

Reto and Thomas decided to design an interface between the PC-1500 and one product currently sold. Their choice was the Commodore floppy 1541. Maybe because it was packed with the power adapter ? And as they had enough space they added a 8bits parallel interface.